1. Field of the Invention
The present invention relates generally to a hand-held dental instrument for intraoral abrading of teeth.
2. Description of the Prior Art
Use of hand-held dental abrading tools utilizing a pressurized slurry of bicarbonate, water and air to clean, polish and/or remove biofilm and heavy stains on the teeth is well known in the dental industry. Such tools operate by directing a gaseous stream mixed with an abrasive material to the tooth surface to be cleaned. The gaseous medium, (often compressed air), and small solid particles comprising the abrasive material are supplied to the tool and are mixed so that the abrasive material becomes entrained within the gaseous medium. The mixture is then discharged through a nozzle upon activation of the tool by the operator. Water is also often provided to dissolve the abrasive material and wash it from the surface of the tooth being abraded. Water may be mixed with the abrasive material internally within the tool or a stream of water may be separately directed from the nozzle to the surface being cleaned. Unfortunately, most polishing tools are somewhat expensive, bulky, prone to clogging and/or are not sterilizable by autoclaving. Accordingly, it would be advantageous to provide a hand-held dental abrading instrument which is easy to manufacture, reliable in operation, easy to grasp and manipulate and fully sterilizable by autoclaving.
It is an object of the present invention to provide a low-cost, easily manufactured dental abrading instrument which is easily grasped and manipulated within the confines of a patient""s mouth.
It is another object of the present invention to provide a handpiece for a dental abrading instrument which is sterilizable by standard autoclaving techniques.
It is yet another object of the present invention to provide a dental abrading instrument having a fully rotatable nozzle which can be gripped comfortably between the thumb and forefinger of the user and which is easily removed and replaced by another similar nozzle when needed.
It is yet a further object of the present invention to provide a dental abrading instrument having a nozzle which provides optimal mixing of a pressurized abrasive stream with a water stream outside and forward of the tip of the nozzle to create a polishing slurry.
It is still another object of the present invention to provide a dental abrading instrument having a self-contained abrasive material supply having means for effectively entraining the abrasive material within a pressurized gaseous medium which is relatively simple and less prone to clogging.
It is still a further object of the present invention to provide a dental abrading instrument having its own light-weight flexible supply cord which is adapted to connect to any existing dental office air/water supply system.
The present invention is a low-cost, reliable compact dental abrading instrument which alleviates the above-mentioned drawbacks. Generally, the instrument includes a light-weight body made from a high temperature material and having internal passageways for permitting fluid flow through the body. A rotatable nozzle having internal fluid conduits therein is mounted on a distal end of the body such that a chamber is formed between the nozzle and the body. The chamber maintains fluid communication between the internal bores of the body and the internal conduits of the nozzle such that the nozzle can be rotated a full 360 degrees with respect to the body.
The body and the nozzle are formed with a coaxial arrangement of cooperative counterbores and barrel sections such that the chamber is defined by a space formed between the body and the nozzle. Preferably, the nozzle is provided with coaxial barrel portions which cooperate with counterbores formed in the body so that the chamber is defined by a space formed between a bottom surface of a larger outer counterbore and a top surface of a larger barrel section fitting therein. Alternatively, a single barrel portion may be provided on an interconnect face of the nozzle which fits within a smaller counterbore formed in the body so that the chamber is defined by a space formed between a bottom surface of a larger outer counterbore formed in the body and the interconnect face of the nozzle. In either embodiment, the body and the nozzle both include primary internal passageways which are axially aligned and in fluid communication with each other and further include secondary internal passageways which are each in fluid communication with the chamber. The primary passageways permit fluid flow of an air/abrasive material mixture and the secondary passageways permit fluid flow of a liquid stream.
The instrument is provided with a unique three-piece nozzle assembly comprising a nozzle grip having a plurality of internally formed passageways therein, a nozzle head having a plurality of discharge ports formed therein and a plurality of elongate extension tubes connecting the internal passageways of the nozzle grip to the discharge ports of the nozzle head. The nozzle arrangement includes a primary conduit terminating at a primary discharge port of the nozzle head for directing flow of the air/abrasive material mixture, and a secondary conduit terminating at a secondary discharge port of the nozzle head for directing a stream of liquid to a surface to be polished. The primary discharge port of the nozzle head is preferably larger in diameter than the secondary discharge port and is disposed at an angle with respect to the secondary discharge port so that the streams of the air/abrasive mixture and the liquid converge at a point a desired distance from the nozzle head discharge ports. In a preferred embodiment, the nozzle grip has a hexagonal cross-section for ease of manipulation. The nozzle assembly is easily removable from the body and may be replaced by another similar nozzle assembly so that the instrument can continue to be used while the previously used nozzle is being sterilized. Additionally, one or both of the elongate extension tubes may be made removable and separately sterilizable to permit enhanced internal cleaning of the nozzle components.
The instrument includes its own light-weight flexible supply line which is adapted to connect to any existing dental office air/water supply system. Differently designed adapters are provided to permit fluid communication between the body of the instrument, the respective conduits of the supply line and the air/ water supply system of the dental office. Depending on the dental office system, an appropriate adapter is selected and installed on the fluid supply line by the user thus permitting connection to any existing dental office air/water supply system.
The instrument also includes a self-contained abrasive material supply which may be connected to the body or which may form a part of the body itself. The supply may comprise an intake or pick-up tube, a cap and a canister which is connected to an abrasive material supply port of the body. The intake tube has a first end generally disposed within the canister and a second end cooperatively coupling the canister to the body. The intake tube is comprised of an inner sleeve, having a first fluid conduit formed therein, and an outer sleeve surrounding the inner sleeve and forming an annular fluid conduit between the inner and outer sleeves. Fluid enters the canister through the first conduit of the inner sleeve, agitates and becomes mixed with the abrasive material in the canister and exits the canister through the annular fluid conduit. The inner and outer sleeves are connected at the first end and the outer sleeve includes at least one opening through a wall thereof for fluidly connecting the canister chamber to the annular fluid outlet conduit.
Alternatively, the body of the instrument itself may form the abrasive material supply. In this embodiment, an abrasive material is contained within a chamber formed by a hollow portion of the body into which an inlet tube and an outlet tube extend. A gaseous fluid enters the chamber through the inlet tube, agitates and becomes mixed with the abrasive material in the chamber and exits the chamber through the outlet tube.
A preferred form of the handpiece, as well as other embodiments, objects, features and advantages of this invention will be apparent from the following detailed description of illustrative embodiments thereof which is to be read in conjunction with the accompanying drawings.